In automation technology, especially in process automation technology, field devices serving to register and/or influence process variables are often applied. For registering process variables, sensors, which are integrated, for example, in fill level measuring devices, flow measuring devices, pressure and temperature measuring devices, pH and redox potential measuring devices, conductivity measuring devices, etc., serve to register the corresponding process variables fill level, flow, pressure, temperature, pH value, or conductivity. Actuators serve for influencing process variables; such actuators can be, for example, valves or pumps, via which the flow of a liquid in a pipeline section or the fill level in a container can be changed. In principle, all devices, which are applied near to the process and deliver, or process, process relevant information, are referred to as field devices. In connection with the invention, remote I/Os, radio adapters, or, generally, electronic components, which are arranged on the field level, are understood to be field devices. Many such field devices are available from the Endress+Hauser group of firms.
In modern industrial plants, communication between at least one superordinated control unit and the field devices occurs, as a rule, via HART technology or a bus system, such as, for example, a Profibus® PA, Foundation Fieldbus®, etc., bus system. The bus systems can be embodied both wired as well as wirelessly. The superordinated control unit serves for process control, process visualization, process monitoring, process documentation, as well as for start up and operation of field devices and is also referred to as a configuration/management system. An operating tool, which runs independently on a superordinated unit, is available under the mark FIELDCARE from the Endress+Hauser group of companies.
Electronic device descriptions are usually applied for integrating field devices into a superordinated control unit. The electronic device descriptions enable the superordinated control unit to be able to detect and interpret data delivered by the field devices. In order that the field devices can be integrated into different fieldbus systems, device descriptions must be created for the different fieldbus systems. In addition to the electronic device descriptions, in increasing measure Device Type Managers (DTM) or device drivers according to the FDT standard are applied, which require a frame application, especially the FDT frame, as a runtime environment. Device drivers serve for comprehensive interaction with field devices.
A measurement transmitter is available under the mark LIQUILINE CM42 from the Endress+Hauser group of companies. Normally a single field device is connected to the measurement transmitter at the field or process level. In a special embodiment, the CM42 transmitter can also be operated with two connected field devices.
At the system level, the CM42 transmitter is connected with a superordinated control unit. In the known solution, the data which can be exchanged between the control unit and the transmitter electronics after the start up of the field device is specified in advance by the device firmware associated with the field device and the corresponding electronic device description or the corresponding device driver (DTM: Device Type Manager) stored in the superordinated control unit. A later change of this default situation is only possible when both the firmware as well as the corresponding electronic device description or the corresponding device driver are modified. The changes are relatively labor intensive and consume much time, and can usually only be performed by the device manufacturer. A flexible adaptation by the user at a later date is not possible.